本文選題：GSM通信 + 語音加密�。� 參考：《西安電子科技大學(xué)》2014年碩士論文

【摘要】：近年來,隨著通信網(wǎng)絡(luò)的不斷發(fā)展和移動(dòng)通信技術(shù)的不斷完善,人們在日常生活中對(duì)手機(jī)等通信設(shè)備的應(yīng)用越來越廣泛,而語音信息作為移動(dòng)通信網(wǎng)絡(luò)中傳輸?shù)淖钪饕畔?其傳輸過程中的安全問題引起了越來越多的關(guān)注。在傳統(tǒng)的語音傳輸系統(tǒng)中,語音信息采用移動(dòng)通信網(wǎng)中現(xiàn)有的安全機(jī)制進(jìn)行加密以確保通話信息不被泄露,是否加密以及加密密鑰都是由運(yùn)營商控制的。隨著業(yè)務(wù)量的增加,通信系統(tǒng)愈加復(fù)雜,其中一些核心的加密算法也遭到破解,原來的安全機(jī)制出現(xiàn)不少漏洞,用戶的通信安全得不到較好的保證,因此,為了保證端到端通信安全,需要一種由用戶控制是否加密并掌握密鑰的加密方法對(duì)語音信號(hào)進(jìn)行加密,使得語音信號(hào)在進(jìn)入移動(dòng)通信網(wǎng)之前就進(jìn)行加密。本文在研究GSM(Global System for Mobile communication,全球移動(dòng)通信系統(tǒng))通信系統(tǒng)工作流程和RPE-LTP(Regular Pulse Excitation-Long Term Prediction,規(guī)則脈沖激勵(lì)長期預(yù)測)聲碼器特性的基礎(chǔ)上,設(shè)計(jì)了一種用于手機(jī)聲碼器之前的模擬語音加密系統(tǒng),并通過仿真驗(yàn)證了該系統(tǒng)的可行性,所取得的主要研究成果為:1.本文在分析GSM語音傳輸系統(tǒng)工作流程及RPE-LTP聲碼器編解碼原理的基礎(chǔ)上,通過借鑒傳統(tǒng)語音加密技術(shù)的思想以及滿足加密語音在移動(dòng)話音通道中傳輸所需要的三個(gè)基本條件:加密語音滿足聲碼器輸入要求、加密語音對(duì)有損壓縮編碼不敏感以及加密語音可以對(duì)抗VAD(Voice Activity Detection,語音活動(dòng)檢測)檢測,對(duì)加密算法進(jìn)行理論分析,提出了一種語音加密方案,以保證進(jìn)入GSM系統(tǒng)前的加密語音在通過聲碼器后不會(huì)出現(xiàn)明顯失真。2.設(shè)計(jì)了一種基于GSM系統(tǒng)的模擬語音加密算法。本算法首先在發(fā)送端對(duì)模擬語音進(jìn)行采樣、分幀和分組。然后,將語音信號(hào)變換到頻域?qū)ζ漕l譜進(jìn)行置亂,達(dá)到頻域加密的目的。最后,將語音信號(hào)變換到時(shí)域,并打亂組內(nèi)幀順序,從而得到可以在移動(dòng)話音通道中傳輸?shù)哪M加密語音。在發(fā)送端也可在語音信號(hào)的頻譜中插入偽譜來改變原始信號(hào)的頻譜以掩蓋語音信號(hào)的音調(diào)特征。在接收端,對(duì)解碼后的加密語音進(jìn)行與加密過程相對(duì)稱的解密。本算直接對(duì)模擬的語音信號(hào)進(jìn)行加密,加密后的語音信號(hào)能夠?qū)挂苿?dòng)通信網(wǎng)絡(luò)中的有損壓縮,更好的保證了GSM通信系統(tǒng)中端到端的安全通信。3.設(shè)計(jì)并實(shí)現(xiàn)了端到端語音加密系統(tǒng)仿真平臺(tái)。基于該平臺(tái),成功進(jìn)行了加密語音傳輸實(shí)驗(yàn),并對(duì)實(shí)驗(yàn)結(jié)果進(jìn)行了分析。實(shí)驗(yàn)結(jié)果證實(shí)了本文設(shè)計(jì)的加密算法是有效且安全的,驗(yàn)證了端到端語音加密系統(tǒng)方案的可行性。
[Abstract]:In recent years, with the continuous development of communication network and the continuous improvement of mobile communication technology, people are more and more widely used in mobile phone and other communication devices in daily life, and voice information is the most important information transmitted in mobile communication network. More and more attention has been paid to the security problems in the transmission process. In the traditional voice transmission system, the voice information is encrypted by the existing security mechanism in the mobile communication network to ensure that the call information is not leaked. The encryption and encryption keys are controlled by the operator. With the increase of traffic, the communication system becomes more and more complex, and some of the core encryption algorithms are also broken. There are many vulnerabilities in the original security mechanism, and the communication security of users is not guaranteed well. In order to ensure the security of end-to-end communication, it is necessary to encrypt the voice signal by a encryption method controlled by the user and master the key, so that the voice signal can be encrypted before entering the mobile communication network. In this paper, based on the study of the workflow of GSM(Global System for Mobile communication, global mobile communication system and the characteristics of RPE-LTP(Regular Pulse Excitation-Long Term prediction, regular pulse excitation and long term prediction) vocoder, An analogue voice encryption system for mobile phone vocoder is designed, and the feasibility of the system is verified by simulation. The main research results are: 1: 1. Based on the analysis of the working flow of GSM voice transmission system and the principle of RPE-LTP vocoder, By using the idea of traditional voice encryption technology and three basic conditions to meet the need of transmission of encrypted voice in mobile voice channel, the encrypted voice meets the input requirements of vocoder. Encryption speech is insensitive to lossy compression coding and can resist VAD(Voice Activity detection (voice activity detection) detection. The encryption algorithm is theoretically analyzed, and a speech encryption scheme is proposed. To ensure that the encrypted voice before entering the GSM system will not appear obvious distortion. 2. 2 after passing through the vocoder. An analog voice encryption algorithm based on GSM system is designed. In this algorithm, analog speech is sampled, divided into frames and packets at the transmitter. Then, the speech signal is transformed into frequency domain to scramble the frequency spectrum to achieve the purpose of frequency domain encryption. Finally, the speech signal is transformed into time domain, and the frame sequence in the group is scrambled to obtain the analog encrypted speech which can be transmitted in the mobile voice channel. The pseudo-spectrum can also be inserted in the spectrum of the speech signal at the transmitter to change the spectrum of the original signal to mask the tone characteristics of the speech signal. At the receiving end, the encrypted voice after decoding is decrypted symmetrically with the encryption process. This algorithm encrypts the analog speech signal directly, the encrypted speech signal can resist the lossy compression in the mobile communication network, and better ensure the end-to-end secure communication in the GSM communication system. An end-to-end speech encryption system simulation platform is designed and implemented. Based on this platform, the encrypted speech transmission experiment is successfully carried out, and the experimental results are analyzed. The experimental results show that the encryption algorithm designed in this paper is effective and secure, and the feasibility of the end-to-end voice encryption system is verified.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN912.3;TN918.4

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本文編號(hào)：1962176